Pain attributed to tissue injury is mainly caused by inflammation. The mechanism of peripheral inflammation includes local liberation of mediators released by cell lysis, inflammatory cells, and nerve endings. Nerve roots are vulnerable to compression (e.g., compressive radiculopathy, infections, and tumors). If the lesion is proximal to the dorsal root ganglion, there may be abnormality of the central axons but not necessarily of the peripheral axons. Therefore, tests aimed at the peripheral axons will not detect the injury in those situations. Likewise, complete degeneration of the axon is not necessary to produce clinical symptoms: lesions may be in the form of perinodal retraction of myelin or frank demyelination. Demyelination with emphatic spread of action potentials between adjacent axons is believed to underlie bursts of lacerating pain because the action potentials transmitted along a few fibers can inappropriately spread many other axons.
Chronic pain is a significant global health, economic and social problem. Complex regional pain syndrome is one of the most severe and mysterious neuropathic pain syndromes. The clinical symptoms of complex regional pain syndrome always include pain, hyperalgesia, and allodynia.
Managing acute and chronic pathology of pain often relies on the addressing underlying pathology and symptoms of the disease. There is currently a need in the art for new compounds for treatment of acute and chronic pain.